From: Antonio Quartulli <antonio@xxxxxxxxxxxxx>
This patch has been added to the 3.12 stable tree. If you have any
objections, please let us know.
===============
[ Upstream commit 377fe0f968b30a1a714fab53a908061914f30e26 ]
A pointer to the orig_node representing a bat-gateway is
stored in the gw_node->orig_node member, but the refcount
for such orig_node is never increased.
This leads to memory faults when gw_node->orig_node is accessed
and the originator has already been freed.
Fix this by increasing the refcount on gw_node creation
and decreasing it on gw_node free.
Signed-off-by: Antonio Quartulli <antonio@xxxxxxxxxxxxx>
Signed-off-by: Marek Lindner <mareklindner@xxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
net/batman-adv/gateway_client.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c
index 1ce4b8763ef2..067996091638 100644
--- a/net/batman-adv/gateway_client.c
+++ b/net/batman-adv/gateway_client.c
@@ -38,8 +38,10 @@
static void batadv_gw_node_free_ref(struct batadv_gw_node *gw_node)
{
- if (atomic_dec_and_test(&gw_node->refcount))
+ if (atomic_dec_and_test(&gw_node->refcount)) {
+ batadv_orig_node_free_ref(gw_node->orig_node);
kfree_rcu(gw_node, rcu);
+ }
}
static struct batadv_gw_node *
@@ -344,9 +346,14 @@ static void batadv_gw_node_add(struct batadv_priv *bat_priv,
struct batadv_gw_node *gw_node;
int down, up;
+ if (!atomic_inc_not_zero(&orig_node->refcount))
+ return;
+
gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC);
- if (!gw_node)
+ if (!gw_node) {
+ batadv_orig_node_free_ref(orig_node);
return;
+ }
INIT_HLIST_NODE(&gw_node->list);
gw_node->orig_node = orig_node;
--
1.9.3
--
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